aarch64 built-in SIMD types

[Tom Kacvinsky]

Hi Kyrylo,

On Tue, Feb 25, 2025 at 4:01 AM Kyrylo Tkachov <ktkachov@nvidia.com> wrote:

> On 24 Feb 2025, at 20:40, Tom Kacvinsky via Gcc <gcc@gcc.gnu.org> wrote:
> >
> > I am trying to find where the aarch64 SIMD built in types are defined in
> > GCC.
> > For instance, __Int8x8_t.  I see some code in gcc/config/aarch64 for
> these,
> > but
> > then it goes deeper into internals of gcc that I don't quite follow.
> >
> > Any help pointing to where I should look would be appreciated.
> >
>
> The logic for defining them is in aarch64-builtins.cc . The information
> about them is tracked in aarch64_simd_type_info structs.
> There’s some preprocessor machinery at work so it may not be obvious how
> it works from a first read.
> There are user-level typedefs in arm_private_neon_types.h that is later
> included standard ACLE headers like arm_neon.h and arm_sve.h
> What particular information are you looking for?
>

I have been playing around with a front end that doesn't have these types
defined so I was looking
to see how they were defined by GCC so I could add them with something
similar to GCC's  -include
option.

Tom